Leakage Of Contents Research Articles

Antibacterial mechanism of vitamin K3-mediated photodynamic inactivation against Pseudomonas fluorescens and its influences on blunt bream (Megalobrama amblycephala) quality

Photodynamic inactivation (PDI) has emerged as a novel non-thermal process technology for inactivating microorganisms due to its low cost, safety, and efficiency. This study aimed to investigate the antimicrobial effect of VK3-mediated PDI against Pseudomonas fluorescens (P. fluorescens) and to assess its impact on the quality of the blunt bream contaminated with P. fluorescens. The inhibition efficiency and photosensitization mechanism were investigated under different VK3 concentrations and UV-A light time conditions. The results showed that PDI could significantly inactivate P. fluorescens >7.0 log10 cfu/ml with 1 mM VK3 and 45 min of UV-A irradiation. Type I and type II photoresponses could co-occur in VK3-mediated PDI by quantitatively analyzing the photoresponse product ROS (OH, H2O2, 1O2). It was observed by SEM and TEM that the combined treatment of VK3 and UV-A disrupted the cellular integrity of P. fluorescens, leading to leakage of cell contents. Meanwhile, it degraded intracellular proteins and destroys genomic DNA, ultimately leading to bacterial death. In addition, the PDI system slowed down P. fluorescens’ proliferation during the blunt bream storage at 4 °C. The PDI system effectively killed 59 % of P. fluorescens on the blunt bream fillets under 1.5 mM VK3 and 60 min of UV-A irradiation. The VK3-mediated PDI delayed pH change and TVB-N production, inhibited protein degradation and fat oxidation, and ultimately maintained the quality of fish fillets. This study provides a promising PDI system for controlling food microbial contamination and maintaining the storage quality of aquatic products.

Discovery of polymethoxylated flavonoids in Artemisia argyi as main active components in inhibiting rice blast fungus

BackgroundRice blast is a devastating disease caused by Magnaporthe grisea, and it is not well controlled globally. As a Traditional Chinese Medicine, Artemisia argyi has been proven to have inhibitory effects on a variety of phytopathogenic fungi. Here, we used bioactivity-guided isolation method and transcriptomics to clarify the antifungal active compounds in A. argyi and their antifungal mechanisms.ResultsIn vitro studies showed that the absolute ethanol extract (AEE) of A. argyi had a strong inhibitory effect on the growth of M. grisea, with a low EC50 value of 1.156 mg/mL, and could cause the destruction of hyphae cell membrane and the leakage of cell contents. To identify the active constituents, we fractionated the AEE using macroporous adsorption resin and silica gel column chromatography. The active fraction (Fr.F-1) was fractionated and had even higher antifungal activity than AEE. The results showed that both AEE and Fr.F-1 could impact primary metabolic pathways and reactive oxygen species homeostasis of M. grisea, decrease the content of reducing sugars and downregulate the expression of genes related to starch and sucrose metabolism. Further fractionation of Fr.F-1 led to the identification of two polymethoxylated flavonoids (eupatilin and 3,5,3ʹ-trihydroxy-7,8,4ʹ-trimethoxyflavone), both of which had antifungal activity and they worked synergistically in Fr.F-1. Finally, we also investigated the effect of AEE, Fr.F-1 and eupatilin on rice blast control. The results showed that AEE, Fr.F-1 and eupatilin application strongly enhanced rice resistance to M. grisea.ConclusionIn brief, these findings indicate that Fr.F-1 subfraction from A. argyi and its main components polymethoxylated flavonoids confer inhibiting activities to M. grisea. This discovery can effectively alleviate the degradation pressure of A. argyi by-products, promote the healthy development of its industry, and provide new a strategy for the development of new botanical fungicides to control rice blast.Graphical

Quaternary Ammonium Salt Derivatives of Hyperbranched Polylysine with Enhanced Antibacterial Activity against Multidrug-Resistant Gram-Negative Bacteria.

Multidrug-resistant (MDR) Gram-negative bacteria infections have gradually become a more serious health problem recently, and antibacterial drugs are urgently needed to tackle MDR Gram-negative bacteria. Herein, we synthesized a series of quaternary ammonium salt derivatives of hyperbranched polylysine (HPL-Cm-n) with different alkyl chain lengths (m = 4, 8, 12, 16) and grafting ratios (n = 5.8-21.0) of alkyl quaternary ammonium salts (Cm). HPL-Cm-ns exhibited excellent antibacterial activities against drug-sensitive E. coli and P. aeruginosa, and specifically, HPL-C12-ns were also highly active against MDR E. coli and P. aeruginosa. The cytotoxicity and hemolytic activity of HPL-Cm-ns increased with the increase in the alkyl chain length and the grafting ratio of Cm. The killing study proved that HPL-C12-9.5 had fast killing kinetics and was bactericidal toward both drug-sensitive and MDR E. coli. The mechanistic studies showed that, similar to hyperbranched polylysine (HPL), HPL-C12-9.5 killed bacteria by disrupting the cell membranes and causing leakage of the cytoplasmic contents. HPL-C12-ns might have potential as an antibacterial agent to combat MDR Gram-negative bacteria.

Purification, characterization, and antimicrobial mechanism of a novel broad-spectrum bacteriocin produced by Lactiplantibacillus plantarum SCA12 from Traditional Chinese Fermented Mustard greens

In this study, Lactiplantibacillus plantarum SCA12, a producer of bacteriocins, derived from traditional Chinese fermented mustard greens was isolated. A novel L. plantarum SCA12-derived bacteriocin, LPsca12, was purified through a multi-step protocol involving macroporous adsorption resin, cation exchange, Sephadex G-25 column chromatography, and reverse-phase high-performance liquid chromatography (RP-HPLC). The molecular mass of LPsca12 was determined to be 1197.0 Da through matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis. The amino acid sequence of LPsca12 was characterized as GLFPSLVRGPR via liquid chromatography-tandem mass spectrometry (LC-MS/MS). Antimicrobial assessment was then carried out, identifying LPsca12 as a broad-spectrum bacteriocin active against both Gram-negative and Gram-positive bacteria, particularly Salmonella paratyphi A. It demonstrates excellent thermal stability (121 °C, 15 min) and maintains its antibacterial activity under acidic conditions (pH 2.0–6.5). Additionally, LPsca12 is sensitive to digestion by pepsin and trypsin. The antimicrobial action of LPsca12 involves compromising the cell membrane integrity, forming pores, and promoting leakage of intracellular contents, which dissipates both the membrane potential (ΔΨ) and cytoplasmic transmembrane pH gradient (ΔpH) of the target cells. These findings suggest that LPsca12 holds promise as a natural biopreservative in food processing.

Quercetin suppresses pyroptosis in mouse fibroblasts by inhibiting the NLRP3/caspase-1/GSDMD pathway

To investigate whether quercetin inhibits pyroptosis of mouse fibroblast NIH-3T3 cells by regulating the NLRP3/caspase-1/GSDMD signaling pathway. NIH-3T3 cells were treated with quercetin or MCC950 (a specific inhibitor of NLRP3) before stimulation with lipopolysaccharide (LPS) and ATP to induce cell pyroptosis. The optimal quercetin concentration and duration were screened using the CCK-8assay after testing various concentrations and times. Morphological changes of the treated cells was observed, and the levels of IL-18 and IL-1β in the cell culture supernatant were detected with ELISA; the protein expressions of NLRP3, cleaved caspase-1, and GSDMD-N and the mRNA levels of NLRP3, caspase-1 and GSDMD were detected using Western blotting and qRT-PCR. The changes in cell pyroptosis were examined with TUNEL staining and LDH release assay. The CCK-8 assay indicated that 24-hour treatment with 20 μmol/L quercetin yielded the most favorable results. LPS and ATP stimulation of NIH-3T3 cells induced obvious swelling, cell membrane rupture and leakage of cell contents, significantly increased IL-18 and IL-1β levels, and enhanced protein expressions of NLRP3, cleaved caspase-1 and GSDMD-N and mRNA levels of NLRP3, caspase-1 and GSDMD. LPS and ATP stimulation also caused a significant increment of TUNEL-positive cell counts and LDH release in NIH-3T3 cells. Treatment with quercetin or MCC950 significantly reduced cell pyroptosis induced by LPS and ATP, lowered the concentrations of IL-18 and IL-1β, decreased the expression levels of NLRP3, caspase-1/cleaved caspase-1, GSDMD/GSDMD-N, and reduced the number of TUNEL-positive cells and LDH release. Quercetin suppresses pyroptosis of mouse fibroblasts stimulated with LPS and ATP and reduces secretion of inflammatory cytokines by inhibiting the NLRP3/caspase-1/GSDMD pathway.

Antibacterial Efficacy of Tryptophan Coordinated Silver Nanoparticles Against E. coli: Spectroscopic and Microscopic Evaluation of Bacterial Cell Death.

The capability of conventional fluorescence spectroscopy and right-angled synchronous fluorescence spectroscopy (SFS) was evaluated to quantify the antibacterial potential of chemically synthesized Tryptophan coordinated silver nanoparticles (Ag-TrpNPs). Silver nanoparticles have gained significant importance as a material of interest due to their diverse assemblies in the nanoscale range and their potent antibacterial activity. But due to toxicity of silver nanoparticles there is a dire need to coordinate these materials with some biocompatible and biodegradable molecules. The study has been focused on chemical synthesis of functional fluorescence nanomaterials based on Tryptophan molecules coordinated with silver nanoparticles (Ag-TrpNPs). The antibacterial activity of Ag-TrpNPs was assessed in bacteria due to their functional characteristics such as tuneability, biocompatibility, and bioavailability. We employed optical characterization techniques such as Ultraviolet-visible spectroscopy, dynamic light scattering (DLS), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), fluorescence spectroscopy, and confocal microscopy to ensure the particles formation in aqueous suspension. DLS analysis confirmed the hydrodynamic size of the nanoparticles of approximately 100nm. SEM images revealed the spherical morphology and size distribution of the Ag-TrpNPs. Escherichia coli bacterial strains were used to assess the antibacterial efficacy of the Ag-TrpNPs using fluorescence spectroscopy and imaging. Initially, the agar well plate method was employed to evaluate the antimicrobial activity of the Ag-TrpNPs. The significant zones of inhibition of size 37mm at 500µg/mL and 27mm at 15.5µg/mL were reported which indicated the efficiency of Ag-TrpNPs from higher to lower concentration. Conventional and synchronous fluorescence spectra provided evidence of bacterial cell death in aqueous suspensions to ensure the interaction of Ag-TrpNPs with E. coli bacteria at different times and concentrations. SEM was employed to investigate the interaction mechanism between Ag-TrpNPs and bacterial cells. The images revealed cell wall disintegration, leading to the leakage of cellular contents, and eventually cell death occurred.

Antimicrobial activity of novel symmetrical antimicrobial peptides centered on a hydrophilic motif against resistant clinical isolates: in vitro and in vivo analyses.

Increasing antibiotic resistance and the paucity of effective antibiotics necessitate innovative antibacterial agents. Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen causing bacterial infections with high incidence and mortality rates, showing increasing resistance to clinical drugs. Antimicrobial peptides (AMPs) exhibit significant potential as alternatives to traditional antibiotics. This study designed a novel series of AMPs, characterized by a glycine-serine-glycine-centered symmetrical structure, and our results indicated that AMP W5 exhibited a rapid and effective bactericidal effect against MRSA. AMP W5 also demonstrated excellent biocompatibility and a bactericidal mechanism that disrupted membrane integrity, leading to leakage of cellular contents. The notable reduction in skin bacterial load observed in mouse models reinforced the clinical applicability of AMP W5. This study provides a promising solution for addressing the increasing threat of antibiotic-resistant bacteria and heralds new prospects for clinical applications.

USE OF GEOSYNTHETICS FOR DEWATERING, CONTAINEMENT AND DISPOSAL OF MINING SLUDGE

Whether it is sludge produced by the technological process of flotation, sludge tailings or sludge produced in another process, which contains pollutants such as heavy metals, it is necessary to dispose it in a controlled manner to reduce the risk for contamination of environment. Mining sludge has been disposed in open basins for decades, recently with measures taken to reduce the possibility of leakage or spillage of toxic contents into the environment. Reduction of the space for permanent disposal of sludge and significant reduction of the risk of spreading contamination is achieved using geosynthetics. In this paper, we will present the concept of dewatering and permanent storage of mining sludge in woven geotextile tubes, as well as the concept of using geosynthetic materials for the safe closure of mining sludge lagoons. Both concepts presented in the paper are accompanied by one case study.

Portulaca oleracea (L.) essential oil inhibits Pestalotiopsis neglecta and controls black spot needle blight in Pinus sylvestris var. mongolica (Litv.)

Black spot needle blight in Pinus sylvestris var. mongolica is a common disease caused by Pestalotiopsis neglecta which leads to yellowing and withering of needles, eventually leading to the death of the affected trees. The study investigated the antifungal activity and mechanism of Portulaca oleracea essential oil (POEO) against P. neglecta and its efficacy in controlling black spot needle blight in Pinus sylvestris var. mongolica. In this study, we identified the main components of POEO as linalool and limonene. The antifungal assay proved that POEO could inhibit the growth of P. neglecta, 6 μL/mL of POEO inhibited P. neglecta by 100 % with an EC50 value of 1.16 μL/mL, and the results of scanning electron microscopy confirmed that POEO inhibited the growth of the P. neglecta mycelium. In addition, POEO treatment induced oxidative stress and exacerbated membrane lipid peroxidation of P. neglecta, which ultimately caused serious damage to P. neglecta cell membranes and cell contents leakage. POEO also reduced the activity and virulence of polygalacturonase (PG), endo-1,4-β-D-glucose hydratase (EG), and pectate lyase (PL) secreted by P. neglecta, thereby controlling black-spotted needle blight of Pinus sylvestris var. mongolica, which was able to control black spot needle blight in Pinus sylvestris var. mongolica. In summary, our results revealed the antifungal mechanism of POEO on P. neglecta and provided potential options for controlling black spot needle blight in Pinus sylvestris var. mongolica and other plant diseases.

H2O2 Self‐Supplying CaO2/POM@MOF Bimodal Nanogeneration Materials for Photothermal and Chemodynamic Synergistic Antimicrobials

ABSTRACTThe emergence of bacterial resistance has a negative impact on the conventional antimicrobial treatments, and research into the development of the new antimicrobial materials is of great significance. Multimodal synergistic antimicrobial materials exert better antimicrobial effects compared with a single modality. In recent years, Polyoxometalate (POM) has shown great potential in the biomedical field due to its high catalytic activity and high photothermal conversion ability. However, owing to its small surface area, its applications have been greatly limited. Herein, we designed a H2O2 self‐supplied CDT and PTT bimodal nanogeneration material (i.e., CaO2/POM@MOF) possessing a larger surface area for the treatment of the bacterial infections, in which CaO2 could release O2 and H2O2 in the weakly acidic microenvironment of bacterial infection and the dual catalytic site of POM@MOF could enhance the CDT reaction to generate ROS, resulting in the bacterial oxidative stress and the leakage of the bacterial contents, and the exposure to the NIR light generates localized high temperature that cause the rupture of bacterial cell membranes and the denaturation of their proteins. Meanwhile, the superior stability of POM@MOF can release fewer metal ions to improve its biocompatibility. The in vitro antimicrobial experiments demonstrated that CaO2/POM@MOF possessed the combined CDT and PTT effect and exhibited excellent antimicrobial efficacy. This work presents a promising strategy to combat the bacterial infections.

Biocontrol of Fusarium oxysporum-infested Gastrodia elata Bl. by Lactobacillus curvatus 2768-VOCs and mechanism of inhibition

Gastrodia elata Bl. Is susceptible to infestation by the fungus Fusarium oxysporum, which can cause severe post-harvest diseases. This paper presents the findings of an investigation into the control and bacteriostatic mechanisms of Lactobacillus curvatus 2768-VOCs on F. oxysporum-infected G. elata. The results of both in vitro and in vivo tests demonstrated that L. curvatus 2768-VOCs exhibited inhibitory effects against F. oxysporum, with inhibition rates of 63.37% and 44.4%, respectively. The results of the in vivo test also demonstrated that the pre-fumigation approach exhibited superior efficacy compared to direct fumigation, with the former showing a preventive effect. Furthermore, it was discovered that VOCs disrupted the integrity of F. oxysporum cell membranes and altered their permeability, resulting in the leakage of cell contents. The fumigation caused damage to the mycelial structure, accompanied by a notable decline in the total lipid and ergosterol content, and an appreciable increase in MDA content. Moreover, the fumigation of VOCs markedly diminished the activities of ATPase and mitochondrial dehydrogenase, thereby disrupting the respiration of F. oxysporum and its energy metabolism. The VOCs were subjected to GC-MS analysis, which revealed that the relative content of acids was the highest, particularly formic acid and glyoxalic acid. The study offers a theoretical basis for the biological control of postharvest diseases in G. elata.

Experimental evaluation of an artificial anal sphincter based on biomechanical compatibility.

The artificial anal sphincter is a device used to treat patients with fecal incontinence who are unable to control their bowel movements on their own. Long-term morphological changes in the tissue surrounding the artificial anal sphincter can cause biomechanical compatibility problems, which seriously affect the clinical application of the artificial anal sphincter. In this paper, the superelasticity of shape memory alloys was utilized to design and fabricate a biomechanically compatible constant force clamping artificial anal sphincter. An invitro simulation system was constructed to verify the effectiveness, safety, and constant force characteristics of the artificial anal sphincter. The experimental results demonstrated that the artificial anal sphincter could be effectively closed with no leakage of the liquid-like intestinal contents, which are most likely to leak. The pressure of the artificial anal sphincter on the intestinal tube gradually increased and eventually became constant during closure, and the pressure value was always less than the intestinal blood supply pressure threshold. In this paper, we designed an artificial anal sphincter based on biomechanical compatibility and the corresponding invitro simulation experimental program and preliminarily verified the effectiveness, safety, and constant force characteristics of the artificial anal sphincter.

Antifungal Activity of Phloroglucinol Derivatives against Botrytis cinerea and Monilinia fructicola.

Naturally derived compounds show promise as treatments for microbial infections. Polyphenols, abundantly found in various plants, fruits, and vegetables, are noted for their physiological benefits including antimicrobial effects. This study introduced a new set of acylated phloroglucinol derivatives, synthesized and tested for their antifungal activity in vitro against seven different pathogenic fungi. The standout compound, 3-methyl-1-(2,4,6-trihydroxyphenyl) butan-1-one (2b), exhibited remarkable fungicidal strength, with EC50 values of 1.39 μg/mL against Botrytis cinerea and 1.18 μg/mL against Monilinia fructicola, outperforming previously screened phenolic compounds. When tested in vivo, 2b demonstrated effective antifungal properties, with cure rates of 76.26% for brown rot and 83.35% for gray mold at a concentration of 200 μg/mL, rivaling the commercial fungicide Pyrimethanil in its efficacy against B. cinerea. Preliminary research suggests that 2b's antifungal mechanism may involve the disruption of spore germination, damage to the fungal cell membrane, and leakage of cellular contents. These results indicate that compound 2b has excellent fungicidal properties against B. cinerea and holds potential as a treatment for gray mold.

Antimicrobial activities of organic solvent extracts of four seaweeds from Oman

Seaweeds are valuable sources of bioactive compounds in biomedicine, cosmetics, food, and pharmacology. The purpose of this investigation was to study the antimicrobial properties of organic solvent extracts from two red seaweed species (Melanothamnus somalensis & Gelidium omanense), and two brown seaweed species (Jolyna furcata & Nizamuddinia zanardinii) compiled from the southern coastline of Oman against several bacterial strains of global health concern (Staphylococcus aureus, Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa) and one fungal strain (Candida albicans). Five organic solvents were used sequentially to achieve extraction. The solvents were applied in the following order: hexane, dichloromethane, ethyl acetate, acetone, and methanol. Only the methanol extract of Nizamuddinia zanardinii (MeNZ) showed interesting antimicrobial activity; the inhibition zone was 13 ± 1 mm. Furthermore, MeNZ was fractionated, and fraction 1 (MeNZ-F1) was recognized to have antimicrobial activity; the inhibition zone was 14.66 ± 0.57 mm. The stock concentration exhibited higher antimicrobial activity compared to the diluted concentrations after 3 h of incubation. The TEM and SEM results indicated that E. coli treated with the active fraction exhibited irregular shape, rough surface, and leakage of cellular content. Additionally, ribosomes were clustered and directed toward the inner membrane of the bacteria, while the DNA clustered in the center of the cell. In conclusion, the methanol extract of Nizamuddinia zanardinii has shown high efficacy against pathogenic bacteria and fungi. Therefore, it can be a valuable candidate for improving/developing antimicrobial drugs in the pharmaceutical and food industries.

Flavonol derivatives containing piperazine and quinoxaline fragments: synthesis and antifungal activity.

A series of flavonol derivatives containing piperazine and quinoxaline had been designed and synthesized. The biological activity test results showed that some of the target compounds had good antifungal activity against various fungi. N5 had the best antifungal activity against Phomopsis sp (P.s.) and Phytophthora capsica (P.c.). The half maximal effective concentration (EC50) was 12.9 and 25.8μg/mL against P.s. and P.c., respectively, which were better than azoxystrobin (Az, 25.4 and 71.1μg/mL). In addition, the protective and curative activities of N5 against kiwifruit were 85.9 and 67.0% at 200μg/mL in vivo, which were better than that of Az (65.9 and 57.0%). The protective and curative activities against chili leaves were 80.6 and 66.5% at 200μg/mL, which were better than that of Az (77.6 and 60.0%). The scanning electron microscopy (SEM) experiment showed that the action of N5 caused the mycelium to bend and fold, changed its morphology and caused damaged to the mycelium. Through the measurement of relative conductivity, leakage of cytoplasmic contents and determination of malondialdehyde (MDA) content indicated that N5 could damage the integrity of pathogenic fungal cell membranes, change the permeability of cell membranes, and affect the normal growth of mycelium.

Antifungal Potential and Mechanism of Bacillus velezensis HeN-7 Isolated from Tobacco Leaves on Bipolaris sorokiniana.

Wheat leaf blight caused by Bipolaris sorokiniana is a widespread fungal disease that poses a serious risk to wheat. Biological control without causing environmental pollution is one of the safest and most effective method to control plant diseases. The antagonistic bacterial strain HeN-7 (identified as Bacillus velezensis) was isolated from tobacco leaves cultivated in Henan province, China. The results of different concentrations of cell-free supernatant (CFS) from HeN-7 culture against B. sorokiniana mycelia showed that 20% HeN-7 CFS (v/v) reached the maximum inhibition rate of 96%. In the potted plants control assay, B. velezensis HeN-7 CFS exhibited remarkable biocontrol activity on the wheat infected with B. sorokiniana, the best pot control efficacy was 65% at 20% CFS. The research on the mechanism of action demonstrated that HeN-7 CFS induced the membrane lipid peroxidation in B. sorokiniana, leading to the disruption of cell membrane integrity and resulting in the leakage of cell contents; in addition, the intracellular mitochondrial membrane potential in mycelium dissipated and reactive oxygen species accumulated, thereby inhibiting the growth of B. sorokiniana. These results indicate that B. velezensis HeN-7 is a promising candidate as a biological control agent against Bipolaris sorokiniana infection.

Effect of different patient positions on endotracheal tube cuff pressure in patients undergoing urological procedures: a prospective study.

The endotracheal tube (ETT) contains a cuff that is placed in the trachea to prevent gas leakage and aspiration of secretions and gastric contents. However, patient positioning after intubation may cause ETT displacement and changes in cuff pressure. Evaluate the effect of different patient positions on ETT cuff pressure in patients undergoing urological procedures in supine, prone, lateral flank, and lithotomy positions. Prospective and observational study. A university hospital in Turkey. Patients who underwent surgeries under general anesthesia in different patient positions were involved. After intubation (T0), the cuff pressure was checked with a manometer and adjusted to 25 cmH2O and continuously monitored. The cuff pressure was checked before (T1) and after achieving the final position (T2) and then at 5, (T3), 10, (T4), 15 minutes (T5) of the position, at the end of the procedure (T6) and before extubation (T7). At postoperative 2nd and 12th hours, the patients were interviewed for sore throat, hoarseness, and cough. The effect of different patient positions on the ETT cuff pressure. 200 patients. The cuff pressure increased significantly at T2 in the lithotomy, lateral flank, and prone groups (P<.001 each). The highest increase in cuff pressure occurred in the prone group (34.3 [7.5] cmH2O). Over time, the cuff pressure decreased in all groups during surgery. Postoperative complications at the 2nd postoperative hour were similar in all groups; however, the mean cuff pressure was significantly higher in the patients with postoperative sore throat or cough (sore throat: P=.003; cough: P=.047). ETT cuff pressures are affected by different patient positioning; therefore, regular recording and adjustment of cuff pressure are necessary for patient safety. We used ETT of a single manufacturer. Therefore, our findings may not be applicable to other types of ETT.

Optimizing therapeutic efficacy of antifungal peptides via strategic terminal amino acid modification

IntroductionAntifungal peptides (AFPs) have the potential to treat antifungal-resistant infections; however, their structure–function relationship remains unknown, hindering their rapid development. Therefore, it is imperative to investigate and clarify the structure–function relationships of AFPs. ObjectivesThis study aimed to investigate the impact of end-tagging single hydrophobic amino acids and capping the N-terminus with glycine (Gly) on the antifungal activity of peptide W4. MethodsThe antifungal efficacy of the engineered peptides was initially assessed by determining the minimum inhibitory concentration (MIC) /minimal fungicidal concentration (MFC), killing kinetics, and drug resistance induction, in addition to evaluating the biocompatibility and stability. Subsequently, the antifungal mechanism was investigated using fluorescence labeling, electron microscopy, reactive oxygen species (ROS) detection, and measurement of mitochondrial membrane potential and apoptosis. The impact of the engineered peptides on Candida albicans (C. albicans) biofilm and their potential application in the scratch keratomycosis model were investigated. ResultsThe antifungal activity of W4 was significantly enhanced by capping Gly at the N-terminus, resulting in a decrease in average activity from 11.86 μM to 6.25 μM (GW4) and an increase in TI values by 1.9-fold (TIGW4 = 40.99). Mechanistically, GW4 exerted its antifungal effect by disrupting the cellular membrane structure in C. albicans, forming pores and subsequent leakage of intracellular contents. Concurrently, it facilitated intracellular ROS accumulation while decreasing the mitochondrial membrane potential. Additionally, GW4 demonstrated an excellent ability to inhibit and eliminate biofilms of C. albicans. Notably, GW4 demonstrated significant therapeutic potential in a C. albicans-associated keratitis model. ConclusionCapping Gly at the N-terminus increased residue length while significantly enhancing the helical propensity of W4, thereby augmenting its antifungal activity. Our exploratory study demonstrated the potential strategies and avenues for optimizing the structure–function relationships of AFPs and developing highly effective antifungal drugs.

Composite Mesh in Incisional Hernia Repair: Unprecedented Gastric Penetration and Gastrocutaneous Fistula Formation

ABSTRACT Hernia repair frequently employs surgical mesh. However, potential complications exist, including mesh migration into adjacent organs, leading to serious outcomes such as enteric fistulas. We report an unprecedented case of composite mesh leading to gastric penetration and subsequent gastrocutaneous fistula formation, identified during endoscopic investigation as a foreign body. A 70-year-old man who underwent right hemicolectomy and incisional hernia repair using composite mesh presented in with symptoms of intestinal obstruction and a small bowel content leak. Following these complications, a small bowel resection was performed, and an ileostomy was created. During an endoscopic investigation, the composite mesh used in the hernia repair during the ileostomy creation was found as a foreign body penetrating the gastric antral area, causing a gastrocutaneous fistula. An exploratory laparotomy was successfully carried out. This case highlights the need to consider mesh-related complications and advocates for research into prevention and management of such adverse outcomes.

Antifungal mechanism of nanosilver biosynthesized with Trichoderma longibrachiatum and its potential to control muskmelon Fusarium wilt

Fusarium oxysporum (Schl.) f.sp. melonis, which causes muskmelon wilt disease, is a destructive filamentous fungal pathogen, attracting more attention to the search for effective fungicides against this pathogen. In particular, Silver nanoparticles (AgNPs) have strong antimicrobial properties and they are not easy to develop drug resistance, which provides new ideas for the prevention and control of muskmelon Fusarium wilt (MFW). This paper studied the effects of AgNPs on the growth and development of muskmelon, the control efficacy on Fusarium wilt of muskmelon and the antifungal mechanism of AgNPs to F. oxysporum. The results showed that AgNPs could inhibit the growth of F. oxysporum on the PDA and in the PDB medium at 100–200 mg/L and the low concentration of 25 mg/L AgNPs could promote the seed germination and growth of muskmelon seedlings and reduce the incidence of muskmelon Fusarium wilt. Further studies on the antifungal mechanism showed that AgNPs could impair the development, damage cell structure, and interrupt cellular metabolism pathways of this fungus. TEM observation revealed that AgNPs treatment led to damage to the cell wall and membrane and accumulation of vacuoles and vessels, causing the leakage of intracellular contents. AgNPs treatment significantly hampered the growth of mycelia in the PDB medium, even causing a decrease in biomass. Biochemical properties showed that AgNPs treatment stimulated the generation of reactive oxygen species (ROS) in 6 h, subsequently producing malondialdehyde (MDA) and increasing protective enzyme activity. After 6 h, the protective enzyme activity decreased. These results indicated that AgNPs destroy the cell structure and affect the metabolisms, eventually leading to the death of fungus.